When she was young, wildlife writer Jane Adams was told ‘you can’t hear bats’ – and believed it for 30 years … But you can.
I was 11 when I first heard a bat. A friend had invited our family to a BBQ and as the sun set and the adults got tipsy, bats appeared. Except I didn’t see them, I heard them. Their high-pitched squeaks and squeals were so loud they seemed to pierce holes in the cooling September air as the bats weaved around my head, catching mosquitoes.
I asked my dad what the bats were saying, and I remember him laughing and telling me, ‘You can’t hear bats.’ And that’s what I believed for the next 30 years.
We have 18 species of bat in the UK, and most are in dramatic decline thanks to modern farming practices killing their food and humans excluding them from roosting in our houses.
The one you’re most likely to come across is the pipistrelle. These tiny bats only weigh between 4-7 grams, have a jerky, erratic way of flying and can eat up to 3,000 flies a night. Although they can see quite well, they navigate and feed in the dark by shouting at very high frequencies and waiting for their shout to echo back – known as echolocation.
The next time I heard a bat, I was on a bat walk organised by Dorset Wildlife Trust. We each had a bat detector, a black box which looked like a small transistor radio. When tuned to the right frequency, the detector allowed us to hear the echolocation calls of the bats as pops, whistles and slurps. It was magical.
Although my dad was right about most things, he’d been wrong about bats. Children, and some young adults, can hear the lower parts of their ultra-sound calls. However as we age the cells in our inner ear become less sensitive and we lose that range – and the ability to hear the bats shouting.
So this month, on a warm evening after the sun has set, take your children or grandkids for a walk in the countryside and get them to listen for bats. Although you probably won’t hear them, it may be your child’s only chance to experience this unforgettable sound with their own ears.
To help bats thrive in the future, go to the Bat Conservation Trust website at bats.org.uk